diff --git a/nova/cmd/manage.py b/nova/cmd/manage.py
index 433ddcbec826..eabb15901682 100644
--- a/nova/cmd/manage.py
+++ b/nova/cmd/manage.py
@@ -960,7 +960,10 @@ class DbCommands(object):
 
     @args('--max-number', metavar='<number>', dest='max_number',
           help='Maximum number of instances to consider')
-    def migrate_flavor_data(self, max_number=None):
+    @args('--force', action='store_true', dest='force',
+          help='Force instances to migrate (even if they may be performing '
+               'another operation). Warning, this is potentially dangerous.')
+    def migrate_flavor_data(self, max_number=None, force=False):
         if max_number is not None:
             max_number = int(max_number)
             if max_number < 0:
@@ -969,7 +972,7 @@ class DbCommands(object):
         admin_context = context.get_admin_context()
         flavor_cache = {}
         match, done = db.migrate_flavor_data(admin_context, max_number,
-                                             flavor_cache)
+                                             flavor_cache, force)
         print(_('%(total)i instances matched query, %(done)i completed') %
               {'total': match, 'done': done})
 
diff --git a/nova/db/api.py b/nova/db/api.py
index 4aad16ce42e3..39e3fe5cd876 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -1952,17 +1952,19 @@ def archive_deleted_rows_for_table(context, tablename, max_rows=None):
                                                max_rows=max_rows)
 
 
-def migrate_flavor_data(context, max_count, flavor_cache):
+def migrate_flavor_data(context, max_count, flavor_cache, force=False):
     """Migrate instance flavor data from system_metadata to instance_extra.
 
     :param max_count: The maximum number of instances to consider in this
                       run.
     :param flavor_cache: A dict to persist flavor information in across
                          calls (just pass an empty dict here)
+    :param force: Boolean whether or not to force migration of instances that
+                  are performing another operation.
     :returns: number of instances needing migration, number of instances
               migrated (both will always be less than max_count)
     """
-    return IMPL.migrate_flavor_data(context, max_count, flavor_cache)
+    return IMPL.migrate_flavor_data(context, max_count, flavor_cache, force)
 
 
 ####################
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index 9dd56ff54dc1..7424886906da 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -6015,7 +6015,7 @@ def _augment_flavors_to_migrate(instance, flavor_cache):
 
 
 @require_admin_context
-def migrate_flavor_data(context, max_count, flavor_cache):
+def migrate_flavor_data(context, max_count, flavor_cache, force=False):
     # NOTE(danms): This is only ever run in nova-manage, and we need to avoid
     # a circular import
     from nova import objects
@@ -6042,10 +6042,11 @@ def migrate_flavor_data(context, max_count, flavor_cache):
         # middle of some other operation. This is just a guess and not
         # a lock. There is still a race here, although it's the same
         # race as the normal code, since we use expected_task_state below.
-        if instance.task_state is not None:
-            continue
-        if instance.vm_state in [vm_states.RESCUED, vm_states.RESIZED]:
-            continue
+        if not force:
+            if instance.task_state is not None:
+                continue
+            if instance.vm_state in [vm_states.RESCUED, vm_states.RESIZED]:
+                continue
 
         _augment_flavors_to_migrate(instance, flavor_cache)
         if instance.obj_what_changed():
@@ -6054,7 +6055,8 @@ def migrate_flavor_data(context, max_count, flavor_cache):
                                        {'instance_uuid': db_instance['uuid']})
                 LOG.debug(
                     'Created instance_extra for %s' % db_instance['uuid'])
-            instance.save(expected_task_state=[None])
+            instance.save(expected_task_state=[instance.task_state],
+                          expected_vm_state=[instance.vm_state])
             count_hit += 1
 
     return count_all, count_hit
diff --git a/nova/tests/unit/db/test_db_api.py b/nova/tests/unit/db/test_db_api.py
index 9e31e848d933..1a6f8963c783 100644
--- a/nova/tests/unit/db/test_db_api.py
+++ b/nova/tests/unit/db/test_db_api.py
@@ -7604,7 +7604,7 @@ class FlavorMigrationTestCase(test.TestCase):
         self.assertEqual(0, match)
         self.assertEqual(0, done)
 
-    def test_migrate_flavor_honors_states(self):
+    def _test_migrate_flavor_states(self, force=False):
         ctxt = context.get_admin_context()
         flavor = flavors.get_default_flavor()
         sysmeta = flavors.save_flavor_info({}, flavor)
@@ -7632,13 +7632,28 @@ class FlavorMigrationTestCase(test.TestCase):
         }
         db.instance_create(ctxt, values)
 
-        match, done = db.migrate_flavor_data(ctxt, None, {})
-        self.assertEqual(4, match)
-        self.assertEqual(1, done)
+        match, done = db.migrate_flavor_data(ctxt, None, {}, force)
 
-        match, done = db.migrate_flavor_data(ctxt, None, {})
-        self.assertEqual(3, match)
-        self.assertEqual(0, done)
+        if not force:
+            self.assertEqual(4, match)
+            self.assertEqual(1, done)
+
+            match, done = db.migrate_flavor_data(ctxt, None, {}, force)
+            self.assertEqual(3, match)
+            self.assertEqual(0, done)
+        else:
+            self.assertEqual(4, match)
+            self.assertEqual(4, done)
+
+            match, done = db.migrate_flavor_data(ctxt, None, {}, force)
+            self.assertEqual(0, match)
+            self.assertEqual(0, done)
+
+    def test_migrate_flavor_honors_states(self):
+        self._test_migrate_flavor_states(force=False)
+
+    def test_migrate_flavor_force_states(self):
+        self._test_migrate_flavor_states(force=True)
 
     def test_migrate_flavor_gets_missing_extra_rows(self):
         ctxt = context.get_admin_context()